Liver may be affected by various pathogenic causes such as viruses, alcohols, chemical substances and undernutrition, whereby hepatic diseases such as acute hepatitis, chronic hepatitis, fatty liver and cirrhosis could be caused. Because there are various pathogenic mechanisms of the development of hepatic diseases and because there are many unknown points involved, a development of a prophylactic and therapeutic agent for hepatic diseases is extremely difficult at present. Presently, the representative drug widely used for the therapy and prophylaxis of hepatic diseases and clinically appreciated includes a glycyrrhizin preparation. However, an efficacy of the glycyrrhizin preparation is not so potent that it should be administered in a large volume through an intravenous drip infusion to develop a certain level of its efficacy. This is disadvantageous because a very heavy burden is imposed on both patients and physicians. Moreover, the glycyrrhizin preparation offers a problem that it has steroid-like side effects, and it is reported that the development rate of the side effects tends to increase when the drug is administered in a large amount.
Under these circumstances, there has been earnestly desired a development of a superior drug which may exert a remarkable inhibitory action against hepatopathy in a smaller amount with a higher safety.
Publicly known are the isoprenylamine derivatives having the general formula (III) ##STR2## [wherein p represents an integer of 2-10, a and b represent a hydrogen atom or jointly form a bond between a and b, m represents an integer of 0-4, R.sub.1 represents a hydrogen atom, and X represents a phenyl group optionally having a substituent on the nucleus] and a pharmacologically acceptable salt thereof, as disclosed, for instance, in Japanese Patent Kokai No. 192342/1982 (corresponding to U.S. Pat. No. 4,514,573) and others.
The isoprenylamine derivatives having the general formula (III) wherein p is 9, a and b jointly form a bond between a and b, m is an integer of 0-2, R.sub.1 represents a hydrogen atom, a lower alkyl group or a nonaprenyl group and X is a phenyl group and pharmacologically acceptable salts thereof are also publicly known and disclosed, for instance, in Japanese Patent Publication No. 53502/1987 (corresponding to U.S. Pat. No. 4,322,555) and others.
Further, the isoprenylamine derivatives having the general formula (III) wherein p is 9 or 10, a and b jointly form a bond between a and b, m is an integer of 1-3, R.sub.1 represents a hydrogen atom, a nonaprenyl group or a decaprenyl group and X is an optionally substituted heterocyclic group and pharmacologically acceptable salts thereof are also publicly known and disclosed, for instance, in Japanese Patent Publication No. 43740/1989 and others.
It is said that these isoprenylamine derivatives have an in vivo inducing action of the interferon which has been currently used for the therapy of viral chronic active hepatitis, and also have an antiviral activity derived from the said action.
However, there have not yet been known the isoprenylamine derivatives having the undermentioned general formula (II) wherein n is 11 or more.